Archive | 10:20 pm

Fruit Fly Battle 2012-13 / Episode 1

18 Sep

The weather is warmer, I’ve sown my seeds and started renewing the beds. Now it’s time to start considering my pest control measures for the coming summer.

Last year I had battles with a few peskies, including:

  • Citrus Leaf Miner
  • Slugs
  • White cabbage moth caterpillar
  • Bronze orange bugs (stink bugs or shield bugs)
  • Aphids

But the mother of all heartbreaking evil was Fruit Fly. They attacked my apples and decimated my stone fruit and tomatoes. I even noticed that a few capsicum were stung late in the season.

Last year I waged an almighty battle against them with exclusion bags, and had some limited success in the apples and tomatoes. I had difficulty bagging some of the fruit, some fruit was stung through the bag when the fruit touched the sides, and another problem was simply having enough bags to cover all the fruit. This year I’m prepared to bag again, but I think I need something else to add to my arsenal.

Eco Naturalure Products

Last week I picked up an eco-trap and some eco-naturalure from the nursery. They are produced by Organic Crop Protectants and are organic measures against Queensland and Mediterranian Fruit Fly. They are approved by BFA and have no withholding periods – you can pick fruit straight after spraying.

I might be a little slow, but I had difficulty understanding the material supplied and the information about the product online, so I thought I’d explain with some pictures.

There are two separate products here. The trap product (eco-lure fruit fly trap) comes with the bag inside. The little white tub is the eco-naturalure – more about that later.

The Eco-Lure Trap

The first step in this process is to set the fruit fly trap. The trap contains both an attractant and a poison.  This is partially a diagnostic measure (it tells you when the flies are active), and also preventative. The trap is hung in your tree, attracts the male fly and kills it so it cannot  mate with the females.

You open the bag and put the trap/lure together. Just make sure you remember to put the yellow lid between the orange hook and the (round) lure. I forgot and ended up having to straighten the hook and weave it awkwardly through the hole in the lid.

You then hang the trap in your tree at about eye level, as straight as you can (which in my case wasn’t really well straight at all).

Once you have caught yourself a male fruit fly, you know that the soil has warmed enough for the young flies to have emerged from their pupae and control measures must begin. This is where the little white tub comes in.

The Eco-Naturalure Spray

The white tub contains a thick brown sticky substance. It is both a protein attractant  for the flies (male and female) and a naturally-derived pesticide, Spinosad. The sticky stuff is watered down 6:1 and sprayed (or painted) onto the trunk of the tree or a surface near the base of the tree.

A word of caution. Spinosad is not only toxic to fruit fly – it will also kill bees. For this reason I won’t be applying it to the foliage anywhere near where the bees are foraging. I’ll be only applying it to the lower trunk of the tree until all the petals have dropped from the flowers. Bees are our friends, and I wouldn’t have any apples at all without them.

Some people apply the naturalure to cards or plastic-covered bait stations, but the instructions recommend the trunk or foliage of the tree itself. The important thing is that the sticky stuff stays damp enough for the flies to feed from, so you can’t paint it onto raw wood or anything that will absorb the moisture in the spray. Rain also washes it away, so you need to re-apply if it gets wet.

So I set my trap in my Dwarf Tropical Anna tree yesterday. And today, the 18th of September – I find this.

Fruit flies – already – in September!

But true to my luck, this afternoon it rained so I couldn’t apply the naturalure. It might even be too late.

Too Late Already?

As soon as the female fruit fly emerges from her pupa, the first thing she does is feed. She feeds from a protein source, usually animal droppings/manure/compost. My chicken coop won’t be helping things here.

If the most attractive thing she finds to eat is the spray, then she dies right there – end of story.  If she eats something else, then she has a chance to mate. She may not even feed again, therefore bypassing any baits and laying her eggs in my tasty fruit – fruit fly win.

So the fact that I caught at least 6 males on the first day I set the trap suggests that they have been active for a while, probably even from August. Some females have already emerged, fed and are ready to lay some eggs. I need to hurry up if I want to have any success of controlling them to any extent.

So this morning after checking my trap I set to work thinning apples and bagging the larger ones with exclusion bags. I thinned more than 100 fruit, with an eye to limiting the number on any one branch, but also thinning those that are in locations that are difficult to bag. I didn’t really even make a dent in the fruit set though – both my warm climate apples have set many hundreds of fruit – much more than the trees can support.

Tomorrow I’ll be spraying the trunks and hoping with all fingers and toes crossed that I’m not too late.

Does anyone have any pest control anecdotes or words of wisdom to share with me?